Soda crystals, bicarbonate of soda and baking soda. Three names, and only two substances behind them. And baking powder, which keeps getting dragged into the same conversation, has nothing to do with either of them.
Short answer
Bicarbonate of soda and baking soda are the same thing. Soda crystals are something else, and much stronger.
Bicarbonate of soda is sodium bicarbonate, and baking soda is simply the other name for exactly that powder. Soda crystals are sodium carbonate: a different substance, around a thousand times as harsh, and not one for bare skin.
The difference between soda crystals and bicarbonate of soda
One thing explains the whole difference: how harsh they are.
| Bicarbonate of soda | Soda crystals | |
|---|---|---|
| Other names | baking soda, sodium bicarbonate | washing soda, sodium carbonate, soda ash |
| How harsh | mild | a thousand times as harsh |
| On your skin | no problem | stings, so wear gloves |
| Gloves | not needed | yes, and keep it away from your eyes |
| Edible | yes, in food grade | no, never |
| Good at | odours, gentle scouring, everyday jobs | baked-on grease, heavy soiling, tiled floors |
It sounds like a small difference. It is a huge one. Soda crystals are around a thousand times as harsh as bicarbonate of soda. That is not a nuance, that is a different product.
And baking powder is something else again. It does contain bicarbonate of soda, along with an acid and a starch. Those two already cancel each other out halfway inside the packet. For cleaning it does nothing for you, and per kilo it costs several times as much.
One more name to keep apart: caustic soda, also sold as sodium hydroxide. It has nothing to do with the other two. That stuff burns through your skin within seconds and does not belong next to the washing-up liquid under your sink. If a recipe says only "soda", do not guess.
Five jobs where soda crystals really are better
Always for the same reason: grease.
- The extractor hood and the hob. A tablespoon in half a litre of hot water. Soda crystals turn grease into a kind of soap, and that rinses away with water. That is chemistry, no scrubbing involved.
- Heavily soiled work clothes. A tablespoon in the drum, alongside your usual detergent. Handy for garden, kitchen or garage clothing.
- Tiled floors that feel sticky. Two tablespoons in a bucket of hot water. Keep it off laminate, parquet, linoleum, marble and aluminium: those go dull.
- The cold oven. As a thick paste, left to sit overnight. Less aggressive than an aerosol oven cleaner, and no smell hangs around afterwards.
- Bins and wheelie bins. Where the smell comes from rotting grease, soda crystals go after the cause instead of masking it.
Where soda crystals do nothing: limescale. Chemically, soda and limescale are too much alike, so soda does not bite into it. For that you need something acidic, and we get to that in a moment.
Whether you need a descaler depends on your postcode
This turns up in none of the cleaning tips, and it makes the biggest difference of all.
How hard your water is varies enormously from region to region in the Netherlands. Across large parts of Limburg, Noord-Brabant and the east of the country the water is hard: there you see white deposits on your tap within a week. In Amsterdam and parts of Noord-Holland the water is soft and that barely happens.
That changes your whole cleaning routine. Live in a soft water area and you almost never need citric acid or cleaning vinegar, while your build-up is probably soap or grease residue, which is exactly what soda crystals are for. Live in a hard water area and it is the other way round.
Your water company publishes the hardness per postcode on its own site, usually in degrees of German hardness. Above 10 you are in hard water. That is five minutes of looking it up, and it decides which of these products you need to bring into the house at all.
The other side: citric acid and cleaning vinegar
Two acids, and they do precisely the opposite of the two powders above.
Soda crystals and bicarbonate of soda go after grease. Citric acid and cleaning vinegar go after limescale. Two different problems, two different answers, and they are not interchangeable.
Citric acid comes as a powder, doses easily and smells of nothing. A tablespoon in half a litre of hot water descales a kettle, a coffee machine or a shower head. Of the two, this is the stronger one.
Cleaning vinegar does the same job more weakly, and it smells. The advantage is that you already have it in the house. The drawback: several appliance manufacturers, Bosch and Siemens among them, advise against repeated use in a machine because of the rubber seals.
The rule in one sentence
Grease you tackle with soda. Limescale you tackle with something acidic.
Remember only this and you get it right nine times out of ten.
What you should never mix
Two mixtures do the rounds everywhere, and one of them is dangerous.
Something acidic with soda: it fizzes, and after that it does nothing at all. Vinegar and bicarbonate of soda together give a lovely foaming reaction, and that is the end of the story. What is left over is a dissolved salt in water, plus carbon dioxide gas. The two effects you were after have cancelled each other out. Take one or the other, never both at once.
An acid with chlorine bleach: that one really is dangerous. The reaction gives off chlorine gas, and that stings your eyes, your throat and your lungs. It applies to vinegar, to citric acid and to a shop-bought descaler just as much. It is enough for both to go into the same toilet bowl shortly after one another. One product at a time, and rinse well before you start on the next.
Why the powder stops halfway, and the bottle does too
A granny trick gets you part of the way. The bottle you reach for next runs into the same wall.
On light build-up a solution of soda crystals really does lift something away. Once it has been sitting there for a long time, a part of it stays put whatever patience you put into it.
The reflex is then to reach for something stronger. That works as well, and it runs into the same thing: a liquid stays on the outside. On a sloping wall it runs off, into a seam it creeps in without staying, into a fibre it never goes deep enough. That is why you have to start over, and why after a year there is a row of bottles under your sink.
Heat works the other way round. Steam goes into the material instead of across it. It softens whatever is stuck and leaves nothing behind for you to rinse away afterwards. Tap water, heated and nothing more, no gloves and no dosing.
And after that you still reach for a cloth. That is the one step that comes back in every case, with powder just as much as with steam. Ours are at streak-free cleaning cloths.
Where to buy it and what it costs
A question that keeps coming back, with a short answer.
Soda crystals and bicarbonate of soda sit on the shelf at the chemist and in the supermarket, with the laundry products or the cleaning products. Citric acid sometimes stands with the preserving jars instead of with the cleaning range. Reckon on a few euros per kilo for all three.
At that price there is no reason not to simply keep a pack of each in the cupboard. It is also why we do not sell them: these are basic products that you can find everywhere.
Frequently asked questions
What is the difference between soda crystals and bicarbonate of soda?
They are two different substances. Bicarbonate of soda is also called sodium bicarbonate and it is mild: you can handle that with bare hands. Soda crystals are also called sodium carbonate, they are around a thousand times as harsh and they sting on your skin. The first is for everyday jobs, the second for baked-on grease, with gloves.
Is baking soda the same as bicarbonate of soda?
Yes. Baking soda and bicarbonate of soda are two names for sodium bicarbonate, exactly the same powder. In the little baking tub you sometimes pay more for it.
Can I use baking powder instead of bicarbonate of soda?
Better not. Baking powder does contain bicarbonate of soda, along with an acid and a starch, and those partly cancel each other out inside the packet already. For cleaning it is of little use, and per kilo you pay several times as much.
What do you use soda crystals for?
Anything greasy: extractor hood, hob, cold oven, tiled floors that feel sticky, heavily soiled work clothes, bins. Against limescale they do nothing, and for that you need an acid.
Why does it fizz when I mix vinegar and bicarbonate of soda?
Because the two eat each other up. What is left over is water with a little salt in it and some gas bubbles. That cleans next to nothing. So take one or the other.
Are soda crystals dangerous for your skin?
They sting. Wear gloves, keep them away from your eyes and store them out of reach of children. They are not edible, unlike food grade bicarbonate of soda.
Which surfaces should soda crystals stay off?
Laminate, parquet, linoleum, marble and aluminium. Soda leaves those dull. If in doubt, test somewhere out of sight first.
My soda crystals have set into one hard lump
They have taken up moisture. Break the lump and dissolve it in hot water, the stuff itself is still fine. After that keep it in a sealed jar rather than in the packet.
Can I use soda crystals in the washing machine?
Yes, a tablespoon in the drum alongside your usual detergent, for very dirty laundry or hard water. It is not a detergent in its own right: there are no surfactants in it.
What is better against limescale, citric acid or cleaning vinegar?
Citric acid. It is stronger, it doses more easily and it does not smell. Vinegar simply happens to be in the house more often. For repeated use in an appliance, Bosch and Siemens advise against vinegar because of the rubber seals.
More around the house
Everything is sorted by job under cleaning products.
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